Used to determine is the state of the subclavian artery

Steps:

1. Physician finds and monitors the radial pulse on the side being examined
2. Patient is instructed to rotate the head toward the side being test and extend the neck.
3. Physician takes the patients arm and extends, abducts to 30 degrees and externally rotates the arm while monitoring the radial pulse
4. The patient then takes a deep breath in and holds it. 

The test is considered to be positive if the radial pulse weakens or fades completely.

Positive test indicates there is compression of subclavian artery (Arterial component of Thoracic Outlet Syndrome)

Video Tutorial: